Members of the Fundamentalist Church of Jesus Christ of Latter Day Saints work around the Yearning for Zion ranch. The FLDS is one of the largest Mormon fundamentalist denominations and one of United States' largest practitioners of plural marriage. The FLDS Church emerged in the early 1900s when its founding members left The Church of Jesus Christ of Latter-day Saints. The split occurred largely because of the LDS Church's renunciation of polygamy and its decision to excommunicate practitioners of plural marriage.